Mental stress hemodynamic responses and myocardial ischemia: does left ventricular dysfunction alter these relationships?

OBJECTIVE

To assess if mental stress hemodynamic responses are impaired and related to mental stress (MS) ischemia in patients with left ventricular (LV) dysfunction.

BACKGROUND

Impaired LV function is an important coronary artery disease (CAD) risk factor and hemodynamic characteristics play an important role in clinical outcomes. Patients with severe LV dysfunction (SLVD) are frequently excluded from prior studies and the effects of LV dysfunction on MS hemodynamic responses are not known.

METHODS

Fifty-eight patients with CAD, consisting of 22 patients with normal LV function (ejection fraction (EF) > or =50%), 16 patients with mild-to-moderate LV dysfunction (30% < EF < 50%), and 20 patients with severe LV dysfunction (EF < or =30) underwent bicycle exercise (EX) and MS testing with 12-lead electrocardiogram and monitoring of vital signs on consecutive days in random order. Blood pressure and heart rate (HR) measurements were obtained. Ischemia was measured using single photon emission computed tomography.

RESULTS

Both MS and EX produced significant increases in all hemodynamic measurements. HR levels were higher both at rest and during MS in SLVD patients. LV groups increased similarly from rest to stress (both MS and EX) for all measurements except HR during MS, which increased more in patients with SLVD than patients with normal LV function. Hemodynamic responses to MS were not related to myocardial ischemia or heart failure symptoms.

CONCLUSIONS

HR response during MS is increased in patients with SLVD, whereas blood pressure responses are similar to those in patients with preserved LV function. Hemodynamic reactivity is unrelated to MS-induced ischemia.